To seal bases against water penetration, water-tight membranes are known in the construction industry. For example, U.S. Pat. No. 4,065,924 describes a barrier layer that is connected to a composite layer, whereby the barrier layer is arranged on the base, and the composite layer ensures the bond with the poured concrete by its being permeated by the poured concrete.
The drawback of such seals is, however, that the barrier layer can become detached from the composite layer, and voids can form between them. In addition, the bond between the barrier layer and the composite layer cannot be caused completely by production, or the composite layer is not completely permeated with the poured concrete. This can all result in voids, which can propagate liquids. In the case of a leak in the barrier layer, caused for example by ingrowing roots, material fatigue or by tensile or shearing forces, penetrating water can affect the barrier layer by these interconnecting voids. As a result, on the one hand, large areas are affected by penetrating water, and, on the other hand, the exact localization of the leak is difficult.